Trip mechanism for automatic weighers



Nov. 14, 1939.

J. B. HOWE V TRIP MECHANISM FOR AUTOMATIC WEIGHERS Filed Dec. 17, 1957 :s Sheets-Sheet 1 fizz/26 71807 cibaepkfl 480608 Nov. 14, 1939.

J. B. HOWE TRIP MECHANISM FOR AUTOMATIC WEIGHERS Filed De.

17, 1-937 3 Sheets-Sheet 2 Nov. 14, 1939. 1 B. HOWE 3 TRIP MECHANISM FOR AUTOMATIC WEIGHERS J0 if @GQMQWWZT? Patented Nov. 14, 1939 UNITED STATES PATENT OFFICE TRIP MECHANISM FOR AUTOMATIC WEIGHERS Appiication December 17, 1937, Serial No. 180,359

5 Claims.

This invention pertains to textile weighing machines and relates more particularly to an improved trip mechanism operative to determine the time of action of one of the parts of the machine. A trip mechanism of this general type is disclosed in the patent to Howe, No. 1,859,444, dated May 24, 1932, the present invention being an improvement upon the device disclosed in said patent.

The present invention is of particular utility when embodied in a card feeder of the Bramwell type. Such a feeder is disclosed in the patent to Howe, No. 1,675,756, dated July 3, 1928. Although the improved feeder of the latter patent has largely superseded the mechanism disclosed in the earlier patent to Howe, No. 1,434,058, dated October 31, 1922, nevertheless the present invention is illustrated as applied to the mechanism of the last-named patent by reason of the greater simplicity of the latter mechanism and the facility with which the construction and mode of operation of the present invention may thereby be illustrated, but without any intention of limiting the application of the present invention to feeders of the earlier type.

In a card feeder such as exemplified in the patents to Howe above referred to, the fibrous material is raised from a hopper or bin by means of an endless spike apron, and delivered by the latter into a scale pan. When a predetermined quantity or mass of fiber has been delivered into the pan, further delivery must stop while the pan is being dumped and restored to load-receiving position. In order to insure accuracy of operation and for stopping the delivery of material into the pan while the latter is being dumped, it is customary to stop the spike apron automatically in response to tilting of the scale beam. Commonly, such stopping of the spike apron is accomplished by causing a stop dog to engageand actuate a clutch release element constituting a part of the drive for the spike apron, the dog being released for movement into engagement with said clutch release element by the action of the trip mechanism. Obviously, in order to insure accuracy of weighing, the spike apron should be stopped as soon as possible after the scale beam begins to tip, but on the other hand, the operation of the trip mechanism and adjunctive parts should not so impede the free movement of the scale beam as to interfere'with its delicacy of response to the mass of material in the pan.

The patent to Howe, No. 1,859,444, above referred to, discloses trip mechanism wholly mechanical in its action, designed to insure improved accuracy of weighing, as compared with prior devices of the same class, and under most conditions this patented trip mechanism is satisfactory for. the purpose. However, in order to avoid'impedance of the free response of the scale beam, and also to furnish sufficient force to actuate the trip mechanism, the mechanical devices employed for operating the trip in the patented mechanism necessarily included lost motion connections and this introduced a time interval between the instant of tipping of the pan and the operation of the trip, which somewhat interferes with the delicacy of operation, especially when each individual Weighing is of very small amount, for example one or two ounces.

The principal object of the present invention is to provide trip mechanism of extremely sensitive character such as to cause stopping of the spike apron with the least possible delay after the scale beam begins to tip, but which will not appreciably obstruct the free tipping of the beam in response to a predetermined load, even though of very small mass. A further object is to provide trip mechanism of simple, durable and inexpensive character applicable to old or new feeders of the general class above referred to, and which is dependable in operation and easily installed and maintained in proper Working condition.

Other objects and advantages of the invention will be pointed out hereinafter in the following detailed description and by reference to the accompanying drawings, wherein Fig. l is a side elevation of a portion of the right side of a card feeder of the general type illustrated in the patent to Howe, No. 1,434,058, but embodying the present invention;

Fig. 2 is a fragmentary side elevation to larger scale than Fig. 1, illustrating details of the im proved trip mechanism, and with the parts in the normal position which they occupy during loading of the scale pan;

Fig. 3 is a view similar to Fig. 2 but showing the parts as they appear just at the instant the scale beam begins to tilt downwardly in response to load;

Fig. 4 is a view similar to Fig. 3 showing the parts in the position which they assume at an almost inappreciable time after they have assumed the relative positions shown in Fig. 3, and showing the dog disposed in clutch-engaging position;

Fig. 5 is a view similar to Fig. 3, but showing the parts in the positions which they occupy as the dog is being restored to its normal position; and

Fig. 6 is a fragmentary plan view of the parts shown in Fig. 2.

Referring to the drawings, the numeral l designates a portion of the frame of a card feeder of conventional type having a shaft 2 which supports and drives the spike apron (not here shown). This shaft is driven by means comprising a twopart clutch 83, one of the elements of this clutch being a pulley it which rotates continuously. The engagement of the clutch parts is controlled by a ratchet wheel 82 which causes the clutch elements to be disengaged so long as the wheel I2 is held stationary by a controller here shown as the pawl I3. Material delivered by the spike apron is deposited in the scale pan l4, fulcrumed at [6 on the duplex scale beam ll which, in turn, is fulcrumed intermediate its ends at 18 upon brackets 89 fixed to the frame of the machine. When a predetermined amount of material has been deposited in the scale pan, the latter overbalances the scale beam and moves downwardly about the axis defined by the pivots |8,-the counter-clockwise movement of the beam being limited by a suitable abutment stop 20. When the scale pan has moved downwardly under the weight of the material deposited therein, it is opened to discharge its load in any suitable way, for example, by the movement of a rod 22 attached to an operating lever 23, hereinafter more fully described. The scale beam comprises an arm ll constituting an actuator for initiating operation of the trip mechanism and which is furnished with a counterweight l'l which acts to restore the scale beam and pan to load-receiving position after dumping.

The improved trip mechanism forming the immediate subject matter of the present invention and which controls the position of the controller pawl l3, and thereby determines the operation of the spike apron, is shown in greater detail in Figs. 2 to 6 inclusive.

Referring to these latter figures, the controller pawl l3 comprises the hub 25 (Fig. 6) which is pivoted to swing freely upon a fixed stud shaft 2'! secured at its rear end in a boss 28 and having a nut 29 at its forward end to retain the controller lever in position. The boss 28 forms an integral part of a bracket 30 which may be secured to the frame l of the card feeder in any desired manner, The controller pawl l3 comprises a counter balancing arm 3| providing with a weight 32 which tends to swing the controller pawl in a clockwise direction about the axis of the shaft 21, thereby to move the end of the pawl 13 into engagement with the teeth of the ratchet wheel l2 so as to stop the rotation of the latter.

For restraining the controller against such movement toward stopping position, there is provided a restrainer device in the form of a bell crank lever mounted to turn on a pin 33 (Fig. 5) projecting forwardly from a lateral extension 30 of the bracket 33. This pin is secured to the extension 33 by means of a nut 34 (Fig. 6) and forms a pivotal support for the hub portion 35 of the bell crank lever. This lever comprises an upwardly directed arm 35 (Fig. 5) and a laterally directed arm 3l. Near its upper end the arm 36 is furnished with a latch shoulder 38 and with an inclined guide surface 38 ,-the latch shoulder 38 being designed normally to engage a pin 39 projecting rearwardly from the controller pawl, l3. So long as the pin 39 is engaged beneath the shoulder 38, the controller is held down in normal inoperative position, as illustrated, for example, in Fig. 2, and when the controller pawl is in this position the ratchet wheel l2 of the clutch device is free to turn, thus permitting the clutch mechanism to drive the spike apron, thereby to deliver fibrous material into the scale pan.

The bracket 30 is provided with a forwardly projecting member 33 which supports the housing 45 of an electromagnetic motor device, for example, a solenoid comprising a coil 4| and a vertically movable core or armature 42. Preferably this solenoid is of alternating current type for convenience in mills provided with alternating current, although it is obvious that a direct current solenoid may be employed if desired. Wires 42 and 43 extend from terminals of the solenoid coil to a socket 44 designed to receive a plug of standard type connected to a flexible conduit leading from a source of electrical current.

Preferably, the lower end of the vertically movable core 42 is furnished with a head 45 which is designed to form a stop for engagement with the frame 40, thereby to limit upward movement of the core when the coil is energized. This head 45 is furnished with a pivot stud 46 which enters a horizontally elongate slot ll in the lateral arm 3'! of the restrainer lever, thereby providing a connection between the core of the solenoid and the restrainer device such that when the core of the solenoid rises, the arm 3'! is swung upwardly and the latch shoulder 33 is thereby released from the pin 39 so as to permit the weight 32 to swing the controller pawl upwardly into stopping position.

A switch support 48 (Fig. 4) is pivotally mounted upon a pin 49 projecting forwardly from the lower part of the bracket 30. This switch support comprises an arm 48 provided with an eccentrically mounted adjustable counterweight 50 whereby the support may be balanced. Normally the switch support is so balanced by means of the weight 50 that the arm 48* rests with very slight pressure against a stop pin 5| projecting forwardly from the bracket 30 and which also forms a limiting stop for the arm 3? of the restrainer device. The switch support 48 is furnished with a pair of downwardly directed lugs 52 and 53, respectively, the latter having a curved slot 54 to facilitate the initial adjustment of the switch housing 55. This switch housing includes a substantially cylindrical tube (Fig. 3) usually of glass, containing a gravity actuated switch element 55, for example a metallic ball or preferably a body of mercury, and near the right-hand end of this tube, as viewed in Fig. 3, there are arranged two contact elements 51 and 58 within the tube, to which are respectively connected very flexible conductors 57 and 58 extending to terminals of the coil of the solenoid. Normally the movable switch element 56 is dis posed at the left-hand end of the switch housing, the latter being normally very slightly inclined downwardly to the left when the arm 38 engages the stop pin 51', The precise initial inclination of the switch housing may be predetermined and fixed by reason of the arcuate slot 54. Preferably a pin 59 projects forward from the lower end of the core 42 for a purpose hereinafter described.

The left-hand end of the arm 48 of the switch support is provided with a pivot pin 50 to which is secured the upper end of an inextensible connecting rod 50', the lower end of which passes freely through an opening in a pin 50 projecting from the arm ll .of the scale beam, the rod having a fixed collar or abutment element 50 normally contacting the pin 50.

The stub shaft 21, which supports the restrainer device, also forms a pivotal support for the hub til (Fig. 6) of a resetting device comprising an arm 61 (Fig. 5) provided with a pin 62 which intersects the vertical plane of movement of the controller pawl l3. The resetting device also comprises an arm 63 provided with a pivot pin 64 to which is pivotally secured the upper end of the resetting rod 65, the lower end of which (Fig. 1) passes loosely through an opening in a guide lug 56 carried by a lever arm 66, and is furnished with a stop 65 at its extreme lower end. The arm 65 forms a part of a cam arm 67 integral with the lever 23, above referred to, said lever also comprising the second cam arm 51 the lever device being pivoted on a fixed stub shaft 68. The cam arms 6'] and 67 are respectively engageable at times by crank pins 89 and H3 carried by a gear H which is driven by means of suitable connections, not shown, from the cardlng machine with which the card feeder is associated. A lever 12, loosely mounted on the shaft 68 and provided at its outer end with a counterweight, carries a stop device 13 whichunderlies the arm 23 and which normally tends to hold the latter arm in the position shown in Fig. 1.

The operation of the device is substantially as follows; it being assumed that the pulley H is being constantly driven and that the clutch device I0 is operative to impart motion to the spike apron shaft 2: The spike apron removes material from. the bin of the feeder and delivers it into the scale pan l4 until sufficient material has been deposited in the latter to overbalance the weight ll Thereupon the scale pan begins to swing downwardly. A very slight upward movement of the actuator arm Il of the scale beam from normal position suffices to lift the connecting rod 56 and thus swing the arm 48 of the switch support upwardly. In Fig. 3 this action is indicated as having taken place, although the tipping of the switch support necessary to accomplish the desired result is exaggerated, as shown in this view. The instant that the switch support swings suiiiciently to cause the mercury to run down and engage the contacts 5! and 58, a circuit is completed through the coils of the solenoid, and the core 42 rises to the position shown in Fig. 4. This action is almost instantaneous and in this respect Fig. 3 may appear somewhat inaccurate, since the movement of the solenoid core takes place so quickly after the switch device tips, that the successive movements of the parts are not readily followed by the eye. When the solenoid core rises, it lifts the arm 31 and swings the latch shoulder 38 from off the pin 39, thus allowing the weight 32 to raise the pawl l3 into engagement with the teeth of the wheel I 2, thereby disengaging the clutch parts and causing the spike apron to stop. After the scale pan has been filled and the scale beam has descended, the rotation of the wheel I! causes the pin 69 to engage the cam arm 61 thereby lifting arm 6'! and pulling the rod 22 down so as to dump the scale pan. As soon as the pin disengages the cam 6'1, the weight at the end of arm 12 swings lever arm 23 upwardly to close the pan. Thereafter, pin 19 engages cam arm 6! and lifts arm 23, thereby restoring the pan to load-receiving position and swinging arm 66 downwardly so that lug (it engages abutment 65 and positively pulls rod 65 downward, thereby swinging the resetting device downwardly and causing the pin 62 to engage the controller pawl l3 (Fig. 5), thereby swinging the latter downwardly until the pin 39 snaps beneath the shoulder 38 of the latch. As the scale beam returns to its normal position, the rod 50 is moved downwardly, thus resetting the switch support 48 to its normal position (as shown in Figs. 2 and 3), thereby breaking the circuit through the solenoid. The parts are thus restored to the original position, and the spike apron resumes its function of lifting material and dropping it into the scale pan.

If during the operation of the machine it be desired to stop the spike apron, it is merely necessary for the operator to lift upwardly on the pin 59, thereby swinging the restraining device and withdrawing the latch 38 from the pin 39, thus allowing the controller pawl to engage the ratchet wheel l2, even though the solenoid has not been energized.

The arrangement just described provides for a most delicate and positive operation of the parts, since the switch support is normally substantially balanced and requires but a slight upward movement of the rod 56" in order to tilt it, and thereby close the circuit. Since the release of the latch is then occasioned by the action of the electromagnetic motors means, to wit the solenoid, the scale beam is not called upon to furnish the energy for stopping the spike apron, and thus even though the machine be set for Weighing out very small quantities of material, it may be depended upon to operate accurately and no matter how delicately the scale beam may be adjusted. Moreover, since there are no lost motion connections between the scale beam and the switch support, the motion of the scale beam is transmitted almost instantaneously to the switch support, so that there is but little lag between the initiation of the tipping of the scale beam and the energizing of the solenoid, and the consequent stopping of the spike apron.

While one desirable embodiment of the inven tion has been illustrated herein by way of example, it is to be understood that the invention. is not necessarily limited to this precise embodiment, but is to be regarded as broadly inclusive of any and all equivalent constructions such. as fall within the scope of the appended claims.

I claim:

1. Trip mechanism for use in a textile machine having movable means for delivering fibrous material, a pivoted controller which, in stopping position, interrupts operation of the fiber delivery means and which, in another position, permits operation of the fiber delivery means, means normally tending to move said controller into the first of said positions, a restraining device nor mally holding the controller in the latter of said positions, and a scale beam supporting a fiberreceiving scale pan and which swings from a normal, pan-filling position to an abnormal, pandumping position in response to the delivery of a predetermined aggregate of fibrous material into the pan by the delivery means, characterized in having an electromagnetic solenoid operative to move the restraining device to abnormal position scale beam that tipping of the latter toward dumping position moves the switch support and thereby places the switch element in circuit closing position.

2. Trip mechanism for use in a textile machine having movable means for delivering fibrous material, a pivoted controller which, in stopping position, interrupts operation of the fiber delivery means and which, in another position, permits operation of the fiber delivery means, means normally tending to move said controller into the first of said positions, a restraining device normally holding the controller in the latter of said positions, and a scale beam supporting a fiberreceiving scale pan and which swings from a normal, pan-filling position to an abnormal, pandumping position in response to the delivery of a predetermined aggregate of fibrous material into the pan by the delivery means, characterized in that the restraining device is a pivoted lever, the trip mechanism including a reciprocable magnetic armature operatively engaging one arm of said lever, an electromagnetic coil for actuating the armature, a switch comprising a gravity-ac tuated contact element operative at times to close the circuit through said magnetic coil, a pivoted support normally holding the switch in open circuit position, and means connecting the support to the scale beam whereby tipping of the latter toward dumping position tilts the support and thereby permits the contact element to close the circuit.

3. Trip mechanism for use in a textile machine having movable means for delivering fibrous material, a pivoted controller which, in stopping position, interrupts operation of the fiber delivery means and which, in another position, permits operation of the fiber delivery means, means normally tending to move said controller into the first of said positions, a restraining device normally holding the controller in the latter of said positions, and a scale beam supporting a fiberreceiving scale pan and which swings from a normal, pan-filling position to an abnormal, pandumping position in response to the delivery of a predetermined aggregate of fibrous material into the pan by the delivery means, characterized in that the restraining device is a bell crank lever having a controller-engaging latch on one arm and having a solenoid core operatively engaging its other arm, and further characterized in that the trip mechanism includes a magnetic coil for the solenoid, a switch comprising a gravity-actuated contact element operative at times to close the circuit through the magnetic coil, a switch supporting lever pivoted to swing about a substantially horizontal axis, the switch being mounted on one arm of the lever, means connecting the other arm of the switch supporting lever to the scale beam whereby the lever is constrained to move with the scale beam as the latter tips toward dumping position thereby to cause the switch element to move to circuit closing position, and means substantially balancing said switch supporting lever thereby to avoid interference with free tipping of the scale beam in response to the load.

4. Trip mechanism for use in a textile machine having movable means for delivering fibrous material, a pivoted controller which, in stopping position, interrupts operation of the fiber delivery means and Which, in another position, permits operation of the fiber delivery means, means normally tending to move said controller into the first of said positions, a restraining device normally holding the controller in the latter of said positions, and a scale beam supporting a fiberreceiving scale pan and which swings from a normal, pan-filling position to an. abnormal, pandumping position in response to the delivery of a predetermined aggregate of fibrous material into the pan by the delivery means, characterized in that the restraining device is a lever provided with a latch on one arm normally engageable with a part of the controller and. in that the trip mechanism includes a solenoid having a movable core, a pivoted switch support, a switch device mounted on the support, said switch device including a gravity-responsive circuit-closing element, means substantially balancing the switch support about its pivotal axis, and a substantially inextensible connecting link uniting the switch support with the scale beam whereby the switch support is constrained to swing in consonance with the scale beam as the latter moves toward dumping position.

5. Trip mechanism for use in a textile machine having movable means for delivering fibrous material, a pivoted controller which, in stopping position, interrupts operation of the fiber delivery means and which, in another position, permits operation of the fiber delivery means, means normally tending to move said controller into the first of said positions, a restraining device normally holding the controller in the latter of said positions, and a scale beam supporting a fiberreceiving scale pan and which swings from a normal, pan-filling position to an abnormal, pandumping position in response to the delivery of a predetermined aggregate of fibrous material into the pan by the delivery means, characterized in having an electromagnetic solenoid operative to move the restraining device to abnormal position thereby to release the controller, a switch element operative to close the solenoid circuit, a pivoted support for the switch element normally holding the switch element in open circuit position, and an adjustable counterbalance for the switch support.

JOSEPH B. HOWE. 

